1. Field of the Invention
The invention is directed to a railway container transhipment device, comprising—preferably two—underframes, an elevating mechanism fixed to the underframe and container clamping elements.
2. Discussion of Background Information
Due to environmental protection reasons, it is a primary goal of the European countries to direct a part of road freight traffic to the railway lines. One problem with this is that at the present it is quite difficult to take over the containers from camions to freight-wagons and from freight-wagons to camions. The containers are most commonly taken over using overhead traveling cranes. The cranes usually lift the containers from the top, which has significant disadvantages in case of electrical railway lines, as these cranes can not be used in case of electrical railway lines. It these cases the wagons are pulled to a railway track with no electrical wire by a diesel locomotive for taking the containers over, which is quite time-consuming and requires significant energy. There are several types of side-lift trucks and loaders as well. These are used where there are no cranes available. Their disadvantage is that they also lift the containers into significant height, so they can not be used with electrical lines. A further disadvantage of the trucks and side loaders is that they can not easily move between the rails and that they can work only at one side.
U.S. Pat. No. 3,637,100 introduces a fork-lift truck, the fork unit of which can be tilted and moved in three dimensions. However, this truck of high mobility can not be suitably used at railway tracks, it can be primarily used in smaller storerooms. Specification DE 2,521,087 describes a self-contained loader device that can be placed on the platform of the transporting vehicle. The loader device is situated on rails fixed on the vehicle. It is a disadvantage of this construction that each transporting vehicle should be supplied with such a device, which would involve unreasonable expenses. Patent specification DE 2,855,665 presents a solution where the containers are taken over by a mechanism with supporting rollers. The camion must range closely to the railway wagon, and the container is translated by rolls of the same level. It is a disadvantage of this solution that it is uncomfortable, and also, each vehicle should be equipped with a mechanism with supporting rollers, which is quite expensive.
Patent specification DE 1,531,990 describes a container handling apparatus which is fixed on a vehicle supplied with wheels, and equipped with an elevating mechanism moving along on rails protruding from the vehicle at its two sides. The elevating mechanism is working between the carrying rails. Its disadvantage is that the containers can only be taken over in restricted circumstances, as the rails carrying the elevating mechanism are situated at the two sides of the container, which also means that the apparatus is only suitable for taking over containers standing alone. However, containers are usually placed close to each other on vehicles, so this apparatus can not be used there.
Patent specifications HU 214,170 and WO 97/03.014 present a container elevating and moving vehicle that can be used at electrical railway lines as well. The vehicle is a double-sided side-loading device with a parallel-moving container catching frame. For taking over a container to the other side the container must be put down, and than the elevating mechanism must be got through under the container so as to catch the container again. The container can be placed on the other transporting vehicle afterwards. It is a disadvantage of this method that the containers can only be caught at their side, therefore it can only be applied with containers that are supplied with catch-holes on their side. It is also disadvantageous that it has several parallel telescopes and surfaces moving near each other, and it is very difficult and expensive to prevent them from dirt and to ensure precise parallelism. This mechanism is not commonly used in practice.
Patent specification WO 01/28.836 published after our priority date presents an improvement of the above mechanism. This mechanism is suitable for catching the container from the top as well with a protruding beam. Similarly to the above one, this mechanism can only be moved parallel to the co-ordinate axis, resulting in several disadvantages. It can only load vehicles standing exactly parallel to the rails. It contains flat sliding mechanisms, where there is significant friction and abrasion, and the mechanism may got stuck. In order to avoid getting stuck, the structure must be very stable and solid from the mechanical point of view, as no elastic deformation is allowed either. The massive structure increases the weight and the cost of the apparatus. It is also disadvantageous that in case of interim placement, the container is supported not at its corner piece, increasing the probability of damage. For taking over a container to the other side the container must be caught again, which increases the cycle time. In case of a container of 8.5 tons, there will be a torque of 22 mt at the end of the upper beam, as a result of which the beam is slightly bent, resulting in a slightly tilted position of the container, which makes the exact positioning of the container more difficult. It also makes the exact positioning of the container difficult that the stabilizer mechanism is not supplied with rolls, therefore no longitudinal adjustment is possible after the container has been caught. The required mid-distance of the rails is 5 meters.